Telephone apparatus.



G. l'. GALITZKA.

TELEPHONE APPARATUS APPLICATION mm mm. 14. 1911'.

Patented Feb. 12, 1918.

i INVENTOR /"f j I UNITED STATES,

PATENT OFFICE.

' enonen, I. enmzxn, or nnw YOBK, may.

TELEPHONE Specification of Letter! Eaten Application filed name 14, 1917. Serial ra ses-1o.

Apparatus, of which the following is a specification.

My invention relates to telephone apparatus, and particularly to one which is adapted to notify and warn the subscriber that the local switchboard operators set is connected in the line and the local operator therefore capable of listening in.

A serious objection to the ordinary form of telephone system is installed in apartment houses and other places where a local switchboard is maintained, is the listeningin of the operator. In a great many instances, this objection to the use of the economical local switchboard, and its associated circuits, has caused the subscribers to install private wires, even though the latter entails a considerably higher rate of telephone rental. Accordingly, an object of my invention is to provide a telephone ap aratus min line,

eluding a local switch oard, w erein the listening-in of the local switchboard operator is reduced to a minimum, if not en tirely revented, by signal in the subscribers set that the operators talking and listening set is connected and reminding the local operator that the subscribers are aware of her listen-- in-in.

n accomplishing the aforementioned ends I have provided'an apparatus in which one of the metallic wires of, the" subscribers line. is utilized, so that the expense-incident:

to the. -instal1ation-of:ingapgaratus is re-;

Ot "er o duced to:ia -minimumzm M jectsl andlad-f vantages'will appearas the description-pro ceeds, wherein 'itristo be understood. that changes in; the

precise embodiment. of the invention can be made: within thes'cope-of what is claimed without departing from the spirit thereof.

The preferred embodiment of my inventallicl;v rej ctions 1 15;:iaelectrically-a -from-t epmaini.

producing a warning one of the contact tion is disclosed in the accompanying di'aw in is, wherein:

ure 1 is a diagrammatic view of a telethe characteristic view of the cif circuit for producing the warning signal is isolated and in no way electrically connected to the telephonic circuits. 1

. Referring s igecifically to Fig. 1, the tele-. phone sets A, C, D and E, represent the ordinary; subscribers phone sets, and are directly connected to alocal switchboard F. The subscribers line circuits 10 lead to the respective jacks'll in the local switchboard,

and are or to one another, by the plugs 12, and their res ective cord circuits 13. i

ev local switchboard operators listenin -in keys 14, which connect theoperators ta 'ng and listening set (not shown) to the cord circuits,- areprovidedi with 'th ortions 1of.;;the.-l1s ning'in ke s-by the in ators 16.-

n order that a signal will connected to the service wires W,-

Patented Feb- 12, 1918.

i at to produce the be produced at the particular subscribers phone setwhois using the phone, that the localswitchboard operator has connected her listening and talkin set into the line, an indicator 17, prefera lymin the form of an electric lamp, is' rovided in each of thesubscribers sets A, C, etc. The electric indicators, preferabl in the form of electric lamps, are electrical y connected to one of the metallic 'wires 18, which.

scribers lmegclrcuits 10. The remote sides connected- 1 to e common return wire 1 19,

:rlisteningiin keys, l The ,com'mon return wire 19fromr-the elec tricalindicators, v

pointsi20' of'each' of the said switches The other. of the contact go to make up the subof the electric indicators 17are' electrically f 9.0, v which,- infturn,, ;isxelectrically connectedl.to i one ;-.s1deaof *the .which 5. arewformed ementsl 15 attached; to :fthe

nd thercontact points-20'.

is connected in parallel to points are connected in parallel by the wire 21, to a source of electrical energy 22. The

source of electrical energy is also connected, i and in parallel, by the .wires, 23, to one wire of the cord circuits 13, which will, when the plugs 12 are inserted in the acks 11, be

, electrically connected to the wires 18 of act arrangement ofcircuits, and the conshown, as it will be readilyapparent tothose the subscribers lines.

With the circuits so arranged, and withone of the plugs 12 inserted in one of the jacks 11, the indicatorin the subscribers set which has been connected in circuit by the plug will be connected to one side of the source of electrical energy 22. Should the operator now depress the listening-in key, the circuit from the source of electrical energy to the said subscribers indicator, will be completed and the indicator will be energized and a warnings'ignal produced. In this connection,'it will be a parent that the indicator, although prefera ly partaking of the nature of an electric lamp, may be of any desired nature, capable of producing a warning signal when "electrically energized, such as a drop enunciator, a bell, etc. An indicator2etis installed in the'local switchboard'F, and is connected to the return wire 19 and to one of the contact points 20 of.

the listening-in key supplemental switches so that this indicator will be flashed when the operators listening-in key is depressed, and i the local switch oard operator will thereby be reminded that the subscribers are aware of her listening-in.

The somewhat modified arrangement illustrated in Fig. 2 is similar to the foregoing, with the exception that the plug 25 and jack 26 are provided with the electrical connec tors 27 and 28, which are independently connected to the signal circuit 29, the latter including a sourceof electrical energy 30, the

supplemental switch 31 (which ismounted upon the operators listening-in key), and

the indicator or lamp signal 32. By so modifying the plug and jack, the signaling circuit 29 is electrically isolated, and independent of the telephone circuit 33. I do notfwish to limit my invention to. the exstructionof the indicators and apparatus as skilled in the art that changes and modifications may be made therein and still attain l r 1. The method of preventing'the listening-in of the operator of alocal switchand accomplishthe aforementioned ends,

and such changes and modifications fallclearly within the scope of my invention.

WhatI claim is board, consisting in providing a signaling apparatus connected with the listening-in key of the local switchboard and reducing a visible warning signal at the su scribers set H switch, a subscrihers upon the actuation of the said listening-in key.

set is connected in line, and an electric circuit including a' source of ener connected to said visible indicator and 'sai switch, said indicator adapted to produce a visible warning signal when the operators talking and listening set is connectedin line.

2.An apparatus of the classdescribed, consisting of a visible indicator at the subscribers set, a-switch adapted to be actuated when the operators talking and listening nected in the aforementioned circuit and adapted to produce a visible warning signal similar to the warning signal of the indicator of the subscribers set.

4. An apparatus of the class described, consisting of a local switchboard including plugs, jacks, and listening-in keys, and subscribers telephone sets, of indicators associated with the subscribers telephone sets, and means whereby the indicator of the subscriber'whose phone set is in use produces a visible signal when a listening-in key of the local operators set is actuated.

5. A telephone apparatus including alocal operators circuit and asubscribers line circuit, a listening-in switch whereby the two are electrically connected, asecond switch mechanically connected to and operated by said first switch, and means electrically connected to said second-mentioned switch adapted to produce a visible warning signal at the subscribers set when the first-mentioned switch is closed.

6. In a telephone apparatus the combination of a local operators switchboard including listening-1n keys for connectin the local operators circuit with the subscrfiiers line circuit, of a switch mechanically connected to-said listening-in key switch and operated thereby, and means electricall connected to said second-mentioned switch adapted to produce a visible warnin signal at the subscribers set when the sai "listening-in key is operated and the local 0 rators circuit connected to the subscribers line circuit. i 1

In an apparatus of the class described the combination with a local op'erators switchboard "including a listening-in key line circuit and local operators circuit, of a switch mechanically connected to and operated by said listeningin key switch," an electric lamp located at the subscribers telephone set electrically connected to said second-mentioned switch and adapted to be energized and lighted when said listening-in key switch is operated and the local operators circuit connected to the subscribers line circuit.

GEORGE I. GALITZKA.

Witnesses:

A. M. Lmmsns'rnmn A. WALSH. 

